The invention relates to fixed ratio planetary type traction roller transmissions.
In traction roller transmission relatively large surface pressures are required for the transmission of forces between the rollers which are in engagement with one another. Depending on the torque transmitted, there are also substantial tangential forces which are effective at the surfaces of the rollers along their lines of contact with adjacent roller or ring surfaces, the maximum tangential forces occurring just before slipping. However, large forces are also effective in axial direction of the traction rollers along their lines of contact with other rollers or the ring surface if the axes of the rollers or the traction ring are not perfectly parallel to one another. In fact, the axial forces caused by misalignment of two rollers which are in engagment with one another are about equal the maximum tangential forces at a given transmission torque. It is therefore important that the traction roller transmission include means which guide the rollers into proper alignment or that the rollers are accurately supported so as to be in proper parallel alignment. Both require relatively expensive and accurately mounted guide or support structures as evident for example from applicant's earlier U.S. Pat. Nos. 3,941,004 or 4,491,038.